Abstract: A piston cylinder device having a piston stroke measurement includes a cylinder tube (1) having an inner tube (2) made of a nonmagnetic material and an outer tube (3) formed on the outer peripheral surface of the inner tube and made of a fiber-reinforced resin material. A piston (76) fixed to a rod (75) is disposed slidably inside the cylinder tube. A stroke detector is composed of a position indicating magnet (80) disposed in the piston and an elongated sensor (81) disposed in the cylinder tube. The elongated sensor includes a thin elongated pipe (82) extending along the cylinder tube between both of its ends and holds at least one magnetostriction line (87) having a large magnetostriction coefficient, a driving coil (84) wound on at least one of the ends of the thin elongated pipe. A pulsed input current to the drive coil causes magnetostriction phenomenon on the magnetostriction line generating an ultrasonic wave.

Abstract: An ultrasonic probe comprising an acoustic lens (20) having a concave lens surface (21) formed on one side of a lens body, and a piezoelectric transducer (23) disposed on the other side of the acoustic lens, ultrasonic waves generated by applying voltage to the piezoelectric transducer being focused through the lens surface to detect the reflected waves of the ultrasonic waves from a sample (26) by the piezoelectric transducer for obtaining information about the surface or interior of the sample. The lens surface (21) of the acoustic lens (20) is defined by an etch profile (15) formed by etching a substrate material (11) which makes up the lens body.

Abstract: An ultrasonic probe comprising an acoustic lens (20) having a concave lens surface (21) formed on one side of a lens body, and a piezoelectric transducer (23) disposed on the other side of the acoustic lens, ultrasonic waves generated by applying voltage to the piezoelectric transducer being focused through the lens surface to detect the reflected waves of the ultrasonic waves from a sample (26) by the piezoelectric transducer for obtaining information about the surface or interior of the sample. The lens surface (21) of the acoustic lens (20) is defined by an etch profile (15) formed by etching a substrate material (11) which makes up the lens body.